And thomas ellis bbown



T. E. BROWN ET AL BASCULE BRIDGE 4g l I '1 N R r 5 I '1' In 7' I;

N nil 5 I w yb Q INVENTORS 76M 2% My Get. 9 1923. 1,470,149

T. E. BROWN ET AL BASCULE BRIDGE 1921 -4 Sheets-Sheet 2 Filed Nov. 8,

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INVENTORS T. E. BROWN ET AL Dct. 1923.

BASGULE BRIDGE INVENTORS 71 6 72 6 gvwm 72 22; QW

4 Sheets-Sheet 3 Filed Nov. 8, 1921 Oct. 9; 1923. T. E. BROWN ET AL BASCULE BRIDGE Filed Nov. 8, 1921 INVENTORS. my 6 ,zrwv

Fig.

Patented a.- 9, 1923. V

UNITED STATES PATENT OFFICE.

THOMAS E. BROWN, OF NEW YORK, THOMAS ELLIS BROWN, JR., OF YONKERS,

NEW YORK.

BASCULE BRIDGE.

Application filed November 8, 1921. Serial No. 513,681.

To a]? whom it may concern Be it known that we, Tnoams E. BROWN and THOMAS ELms Bnowx, Jr, residing, respectively, at the city of New York and at the city. of Yonkers, in the county of Westchester' and State of New York, have invented new and useful Improvements in Baseule Bridges, of which the following a specification.

This invention relates to improvements in bascule bridges, and the principal objects of the inventionare to balance the movable span ofa bascule bridge by means of a simple mechanism readily adaptable to a variety of conditions and to provide through the medium of said mechanism a simple and positive means for opening and closing the movable span, thereby avoiding the racks or gear segments usually necessary.

lVe accomplish these objects by associating the counterweight with the movable span of the bridge by means of articulated polygonal frames or linkages, pivots of which are constrained to move in paths such that the linkages form a parallel motion with relation to certain geometric lines hereinafter described, and also, by supporting pivots of said linkages by wheeled trucks carrying substantial loadings, we are enabled to open and close the movable span by simple rotation of the wheels of the trucks, and we accomplish a further object of our invention by introducing limit stops for said wheeled trucks and said linkages whereby the moving span issupported in and so is adapted for use in double-leaf bridges.

Referring to the drawings which accompany thespecification to aid the description:

Fig. 1 is a side view, in partial section, of :1 bridge of our construction.

Fig. 2 is an end view ofFig. 1.

Figs. 3 and 4 are enlargedviews of portions of Figs. 1 and 2, Fig. ,3 being an end view of the portion shown in Fig. 4.

Fi 5 i a side view of a double-leaf bridge with long approach spans.

. 6 is a half plan view of Fig. 5. p

7 is asectionalview of portions of at larger scale, overlapping portions beingdotted for clearness, and Fig. 8 is an end v1ew of the parts indicated in Fig. 7.

Figs. 9, 10, 11, and 12 are explanatory diagrams showing various forms of our construction.

Fig. 13 is a heel balanced plate girder railroad bridge. Figs. 14: and 15 are special forms of our invention.

Similar characters refer to similar parts in all the figures In general letters refer to geometricfeatures which may or may not coincide with material elements and numerals refer to material parts of the structure.

Referring to Figs. 1 and 2: 1 is the movable span of the bridge, P the pivots about which it rotates, 2 a fixed approach span, shown in longitudinal section for clearness, 3 is the roadway, elis the toe pier, and 5 are piers'supporting the fixed structure, the foregoing parts forming the bridge structure proper as distinguished from the balancing and perating structure.

6 is a longitudinal frame which carries the track 7. Said frames 6 are supported laterally by'braces15 shown in Fig. 2.

S is a counterweight carried by the counterweight members 9, said members 9 being pivoted at O to a truck memberlO, having rollers 11 and girders 12, said truck member 10 forming a traveling cross girder spanning the roadway and adapted to move backward and forward on tracks 7 in the manner of a traveling crane.

Members 113 and 14 are pivoted struts or links pivotally conncctingthe truck member 10 with the trusses 16 of the movable span land the counterweight member 9 with the bridge structure. Said struts 13 andfld are preferably parallel and of equal length and .with'the parts described form a fiexiblehexagonal polygon P-b()' Oa-P, constituting a polygonal linkage in .which opposite sides are parallel and .which is supported and stabilized by the truck member 10 at the apeXes O and O.

and R the secondary cit counterweight ra- 7 takes of the horizontal motion of th men'iber 10, and therefore said. geomc ric axis is" 'onstrainedto move in a horizontal line, and the linkage shown forms a parellel' motion which maintains parallelism between the counterweight member 9 and the movable span 1 and thereforemaintains the sec ondary radius R parallel to the primary radiusll, and in consequence, as will be explained hereinafter, themoving span 1 is balanced in all its positions by the counterweight 8.

The extreme positions of the truck mem ber 10 andcounterweight 8, when the movablespan is in its fully opened position, are indicatedby the dotted lines, and. the extreme positions of the linkage members are indicated bycbrokenlines;

Inthe form shown in Fig. 1 the counterweight 8 preferably extends across the road way 3 and is-above the trafiie clearance line 26 when'the span is closed, as shown in Fig. 2.

In this form the counterweightmembers 9 and the links13 and 145 preferably lie in the plane of thetruss '16 of the movable spanl and the track? liesoutside of said plane, but these positions may be inter changed, orif theqwidth of the bridge permits, the frame 6 and track 7 may be placed inside of the plane'fof the truss. v In either case an importantfunction of the traveling cross-girder or truck member 10 is to transfer the loadings from the planes'of the linkages tov the planes of the tracks.

It will be understood that when in the descriptionbut one side of the bridge is referred to the parts described will in general be duplicated on the other side of the bridge.

Referring more especially to Figs. 3 and t, the bridge may be operated in any suitable manner, but we prefer to open and closethe movable span by moving the truck member 10 backward and. forward by rotating some or all of the wheels or rollers 11, for, as will be readily understood from Fig. 1,

when the wheels 11 are rotated counterclockwise the travelingcross girder or truck member 10 will .move baclnvards and the span Lwill open,and when said wheels are rotated; clockwise the truck member 10 will moveforward and the span 1 will close.

.The load on the'truck-n'iember 10 will be. constantduring the whole motion and will beequal to the-weight ofthe counterweight '8' plus the weight of said truck member '10 itself; hence there will al ays be ai'nple, and

usually much more than ample, adhesion between. the. wheels 11 and t acks for operation of the span.

said l, but is omitted from Fig. 1 for clearness of the drawing.

Electric current for operation and control of the motor 18 may be carried to the traveling crossgirder 10 by trolley or flexible wires or in any other suitable manner.

The operator maybe stationed at any conrenient part of the structure or may ride backward and forward with the traveling cross-girdcr 10 as is the practice with travel mg cranes. It will be readily m'iderstood that an in ternal combustion engine or other motive power may beused instead of the electric motor 18. I

Referring to 5 and 6: Fig. 5 is a side elevation of a double-leaf Wridgehaving ion; approach spans, only the left hand end of the structure being shown in the figures, and it will be understood that the structure shown is repeated on the right hand. end,

the broken line 22 representing the center same plane," and also that the lateral and sway bracing 20 of the fixed structure 2 should be of the usual construction, and we therefore prefer in this form to place coun terweights 8 outside of the trusses 19 of the fixed structure 2, and to place the tracks 7 on the trusses 19 of the approach span 2.

In Fig. 5 thelinkage shoWn is a parallelo 'ram 1 -O a, formingv a simple paral- 'lei motion, the pivot atfOf being preferably in this form on the counterweight member 9,

the link 13 being connected to said member 9, nstead of directly to the truck member 10.

The operation of the bridge willbe understood from the description of the operation of the form shown in Fig. 1.

In double-leaf bridges, there being no pier to support the toe end of the moving leaf,

provision must be made to enable the mov able span to support the live .load. This may be accomplished by locking together the chords of the trusses 16 at the center line of the brldge so that the two leaves may act as a simple span. but we prefer to introduce a stop 21, see Fig. '7. on a fixed part of the structure, such as lon'gitudii-ia'l frame 6, to

arrest the motion of the linkage and truck member when the span is in its closed position and enable the link 13 to positively support the leaf when in said closed position so said leafmay act as a cantileverI This will be-better understood by again referring to Fig. 8, in which such a stop 21 is indicated by dotted lines, and a'stop member or girder 22 is shown by dotted lines as attached'to link 18 in proper position t engage stop 21 when the span is in its closet position. Obviously the stop 21 and stop member 22 are not needed in Fig. 1 unless the toe supporting pier 4 is removed and hence are not shown in that figure.

Referring again to Figs. 5, 6, and 7', it will be noted that the plane of the linkage is outside of the plane of the truss 19, as more clearly shown in 8, hence the counterweight effect must be transferred between said planes. This may be effected by thestiflness of the traveling cross-girder or truck member 10 if desired, but we prefer to accomplish this transference by means of across frame 28 (see Fig. 6) connecting the links 13 on the two sides of the bridge and to introduce additional parts 2a into the construction of links 13, said parts 24 carrying the stop member which in this case may be a simple pin 22, and thus when the leaf 1 is in its closed'position and said pin 22 has engaged stop. 21, the parts 24 form a direct connection in the plane of the trusses between the movable leaf and the fixed span. The normal motion of pin 22 will be readily understood from the dotted position of said pin shown in Fig. 7. The stop 21 maybe placed on any suitable part of the fixed structure and may engage any snitablecpart of the truck member 10 or any suitable part of the linkage system, but we prefer the arrangements shown in Fig. 3and in- Fig. 7.

The parts 24 may be pivoted as at 25, to allow said parts to, adjust themselves to irregularities of alignment. The amount of adjusting motion around pin 25 may be limited in any suitable manner or pin 22 may be allowed to rest on and slide backward 1 1 nd forward on track 7 when-the leaf 1s in iInotion.

"trio axis combined with a motion of that 1, and balance depends 'on the relation-v ship of t\vo ,--geo'metric: lines and said axis.

These lines are the prime radius or line qioiningthe*pivotal point of the movable seen with its center of gravity and the secondary radius r line joining the geometric axis with the center of gravity of the counterweight, the secondary radius having a length equal t the length of the prime radius multiplied by the ratio of the weight of the movable span to the weight of the counterweight.

Vi e call these lines and axis geometric for theymay or may not coincide with material .structure and their existence may be purely mathematical.

It may be readily proved that a span rotating about a horizontal axis will be in balance in all its positions with a counterweight, having rotation inthe same sense or angular direction as said span, if the prime radius and secondary radius remain parallel throughout the motion and the geometric axis moves in a horizontal line. This is the principle of our invention.

Referring to'the diagram Fig. 9: 1 represents a movabl span in any position P its pivot and G. 9. its center of gravity, and 8 represents a counterweight and G its center of gravity. eC. g. is a line of indefinite length drawn through the pivot P and center of gravity C. 9. The portion of this line which extends from P to G. g. is the prime radius R. 0(Z is a line of indefinate length passing through the center of gravity G of the counterweight 8 and which is parallel to the prime radius B. On said line ccZ beinning at the center of ravit of the counh n h te-IWeight G, a length G() is laid off equal to RX in which B represents the weight of the bridge and W represents the weight of the counterweight and R the length of the primeradius. The point 0 is then the eometric axis and G-O is the secondar and vO-a, are used to connect the'line of -d of the secondary radius R with the line of the primary radius R, then said radii R and R- must remain parallel throughout any motionof the span 1, and further, if the geometric axis 0 is supported, as by a truck member represented by roller 10 on ahor'- zontal track 7, the said geometric axis (l will be constrained to move in a horizontal line and the conditions of balance be fulfilled.

Referring to the linkage P-GOa shown by the solid lines in 9, which is a simple parallel motion and an elementary io-rin of my invention, it should be noted 5 iaciied to a member represented by the link O may beri-gidlv attached to memi represented bythe link P-G, or may from the point as indid lines in the figure, as in ,0 conditions of balance will be her case i Thile parallelism is obtainedby any two parallel links joining the lines. of: the prime and'secondary radii, it should be noted that the linksshould not be parallel to the line PO, as in that case there would beno motion of the geometric axis and the span could notbe operated by moving that axis and animportant object oi? the invention would be defeated.

The amount of the horizontal motion of h geometric; axis is dependent on the an-. gular'ity of the. linkage with the line PO, and by choosing suitable angular position for; the linkage this .motion may be, made greater or less as desired.

Coincidence ot the geometric elements with material structure ris not essential for, referring to Fig, 10. the counterweight 8 may ,be attached to the member 14:, and truck member; placed at any point on the line P. (has 0 and a linkage P*bO-a be used, similar tothe geometric parallelogram R'GOh, and the geometric axis will still travel in a horizontal line and the secondary radiusR remain parallel to the prime radius R, notwithstanding that these are now. only geometric elements in space.

,lVe may also, as shown in F 11, use a simple linkage O.(vfP-Z) in which b-O and" P-a are parallel and at cqual angies (3 with the secondary and primary radii R and R, the counterweight 8 being carried on a suitably shaped. member 9, pivoted to the truck member 10 at the geometric axis 0.

Other forms of parallel motion linkages will suggest themselves, as for instance the torinshown-in Fig. 12 in which the pivot P is on a fixed part of the bridge structure, and the linkage PP-.7)-1010a is hexagonalandis supported by an extended truck member 1O-10. f fllheiorms shown in Figs, 9, 10, 11, and 12 readily be adapted to double-leaf bridges by introducing a stop 21 of any suitable construction on the fixed structure which will engage the movable mechanism and prevent further forward motion of truck member '10 when the leaf arrives at its lowered position,

- The simpleparallel motions hereinbetore described have straight horizontal tracks, but curved or .inclined tracks may often be desirable, as for instance when the movable spaniscarried at the end of along approach span having curved or inclined chords.

In such cases, referring again to Fig. 11, the "Frame 9jmay be extended and the track fu emberplaced at a point other than O, as at Oas. shown by the dotted lines, and byusing a suitablyciurved track 7 the geometlric axis0-,willstill'travel in a horizontal line and-the secondary radius R remain parallel ,to the primary radius R. Similarly in Fig. 10, by placing the truck lemm member 10 at some point other than 0 as 0" an inclined and. slightly curved track 7" will fulfill the conditions of balance as described.

From the foregoing description it will be clearly understood that our invention involves a parallel motion with respect to the primary and secondaryradii as described, but that it is not essential that the material parts of the structure have bet-ween themselves any parallelism whatever. i

\ This is clearly illustrated byFig. 13 which shows a plate girder railroad bridge partially heel balanced.)

In this form the counterweight 8 is rigidly attached to member 14 which is pivotcd at l to therearwardly. extended end of the movable snarl 1, and the linkage is a quadrilateral. -b-O'a in which the links are not parallel, but nevertheless by means oi the peculiarly curved profile of the track 7 the geometric conditions of balanceare preserved and the movable span is balanced in allfits positions.

Fig.- l lshows a'special case in which the linkage is positioned relatively to the counterweight 8 and span 1, by rotating the links 9 and 13, truck member 10 and track .7 bodily about; the pivotP, and thus said track 7 becomes, an inclinedstraight track, anarrangement which fulfills the conditions oil balance and will be occasionally useful.

ciple to a double-leaf span in which the .couuter veight' is vertically over its pivot reghen the span isin its closed position. In this form also, anomalous as it may seem, the movable leaf is balanced'in all its positions and no power is'required to move the leaf other thanthat necessary to over- 1 omeiiricti0n and wind pressure.

' Now, having describedour improvements, what we claim' as our invention is: i

1. In a bascule bridge, a movable span,

Ta counterweight carrying member, a supfport"fo r said member adapted to travel backward and forward on a fixed partof the bridge structure, and links associating said member with said span said support and said links adapted to move the geometric axis in a horizontal line and maintain the secondary radius always parallel as the primary radius. f

Ina b'as oule bridge, a pivoted span, 'a counterweightcarrying member, a support for said member adaptedto travel mickward and forward on a fixed part of the bridge structure, saidsupport pivoted to said member. parallel links associating said member with said span and said links at an angle with the line joining the pivot of said span and the'pivot of; said support, 'whereby movement of saidsupport imparts rotation to said span. Y

F in; 15 shows an application of our prinios weight with said span and a support-for said linkage adapted to travel backward and forward on said fixed part as said span rotates to its open and closed positions.

4. In a bascule bridge, a movable span rotatably mounted on a fixed part of the structure, a counterweight rota-table in the same direction angularly as said span, a

polygonal linkage operatively associating said counterweight with said span, a support for said linkage adapted to travel backward and forward on'said fixed part,

and arresting means adapted to engage said i'i'iX8Cl part and prevenlt further forward movement of said support when said span arrives at its lowered position.

In a bascule bridge, a rotatable span, a counterweight rotatable in the same di rection angularly as said span, a polygonal linkage operatively associating said counterweight with said span, a support for said linkage and means to move said support backward. and forward and open andclose said span. 7 i

6. In a bascule bridge, a movable span, counterweight, a polygonal linkage operatively associating said counterweight with said span and a support for said linkage constrained to travel backward and forward in a path so shaped that the geometric axis travels in a horizontal'line, and the second-- ary radius is maintained parallel to the primary radius during the entire motion of said span. 7 i

7. In a bascule bridge, a rotatable span, a counterweight rotatable in, the same direc tion angularly as said span, a polygonal linkage operatively'associatin said counterweight with said span, a traveling crossgirder supportin said linkage and spanning the roadway of said bridge, and means to move said cross-girder backward and forward to open and close said span.

8. In a bascule bridge, a movable span, a truck member adapted to move backward and forward on a suitably shaped track, pivoted members associating said truck member with said span, one of said pivoted members carrying a counterweight, said members constituting a linkage, and said track and said linkage adapted to move the geometric axis in a horizontal line and maintain the secondary radius always parallel to the primary radius.

9. A bascule bridge, a movable span, a substantially horizontal track, a wheeled truck adapted to move backward and forward on said track, a counterweight carrying member pivotally connected to said truck, a link connecting said truck with said span, a second link connecting said menber .with the bridge structure, said link forming a parallel motion whereby said counterweight carrying member is maintained in parallelism with said span, and

means to rotate the wheels of said truck to move said truck backward and forward and open and close said span.

10. In a bascule bridge comprising a movable span, a counterweight, members carrying said counterweight rotatable in the same direction angular as said span, means associating said members with said span and tracks to support said members, said tracks and said members lying in parallel planes; a traveling cross-girder spanning the roadway of said bridge and carried on said tracks and adapted to transfer the counterweight load from the planes of said members to the planes of said tracks.

11. In a bascule bridge comprising a fixed structure, a. movable span, a counterweight rotatable in the same direction angularly as said span and members associating said counterweight with said span; a member relatively movable and permanently connected with said span which engages said fixed structure when said span is closed and supports said span when in its closed position.

.12. A bascule bridge having a span .rotatable about a fixed pivot, a counterweight rotatable about a movable pivot and means whereby, for any movement of said span, the angular motion of said counterweight about its movable pivot is equal to the angular motion or" said span about its fixed pivot.

18. A bascule'bridge, having a rotatable span, a counterweight rotatable in the same direction angularly as said span and means, associating said counterweight with said span, adapted to move the geometric axis in a horizontal line and maintain the second- 'ary radius always parallel to the primary radius."

THOMAS E. BROWN. THOMAS ELLIS BROWN, JR. 

